diff options
authorJohannes Weiner <>2012-12-06 15:23:25 -0500
committerLinus Torvalds <>2012-12-08 08:41:18 -0800
commited23ec4f0a510528e0ffe415f9394107418ae854 (patch)
parent684c9aaebbb0ea3a9954d605d4908e650659e7db (diff)
mm: vmscan: fix inappropriate zone congestion clearing
commit c702418f8a2f ("mm: vmscan: do not keep kswapd looping forever due to individual uncompactable zones") removed zone watermark checks from the compaction code in kswapd but left in the zone congestion clearing, which now happens unconditionally on higher order reclaim. This messes up the reclaim throttling logic for zones with dirty/writeback pages, where zones should only lose their congestion status when their watermarks have been restored. Remove the clearing from the zone compaction section entirely. The preliminary zone check and the reclaim loop in kswapd will clear it if the zone is considered balanced. Signed-off-by: Johannes Weiner <> Reviewed-by: Rik van Riel <> Signed-off-by: Linus Torvalds <>
1 files changed, 0 insertions, 3 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 124bbfe5cc52..b7ed37675644 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2827,9 +2827,6 @@ out:
if (zone_watermark_ok(zone, order,
low_wmark_pages(zone), *classzone_idx, 0))
zones_need_compaction = 0;
- /* If balanced, clear the congested flag */
- zone_clear_flag(zone, ZONE_CONGESTED);
if (zones_need_compaction)